It Had Been Thought That Brassica Nigra Competitively Displaced the Native

It had been thought that Brassica nigra competitively displaced the native grass Nassella pulchra, but Orrock et al. showed that it was likely apparent competition when

A) B. nigra shaded out N. pulchra.
B) N. pulchra did not germinate near B. nigra.
C) B. nigra sheltered mammal herbivores which consumed N. pulchra.
D) B. nigra had higher survival after fire than N. pulchra.
E) All of the choices are correct.